view model and view not syncing about vue.draggable HOT 7 CLOSED

                getQuestiongroups: function(){
                    this.$http.get('admin/osamaker/api/group/get')
                        .then(function (data){
                            this.$set('questiongroups', data.data);

                    })
                    .catch(function (err){
                        console.log(err);
                    });

    public function getAction(){
        $questiongroups = Questiongroup::query()->related('questions')->get();

        foreach($questiongroups as $questiongroup){
            $questiongroup->questions = array_values($questiongroup->questions);
        }


        return array_values($questiongroups);
    }

                           Questions Json 

                            [
  {
    "id": 77,
    "questiongroup_id": 1,
    "text": "Question 1",
    "question_order": 1,
    "options": [],
    "data": [],
    "created_at": {
      "date": "2016-07-30 09:03:17.000000",
      "timezone_type": 3,
      "timezone": "UTC"
    },
    "modified_at": null
  },
  {
    "id": 78,
    "questiongroup_id": 1,
    "text": "Question 2",
    "question_order": 1,
    "options": [],
    "data": [],
    "created_at": {
      "date": "2016-07-30 09:03:21.000000",
      "timezone_type": 3,
      "timezone": "UTC"
    },
    "modified_at": null
  }
]